(6aR,9aS)-2-(cyclopropylmethyl)-5,6a,7,8,9,9a-hexahydro-5-methyl-3-(phenylmethyl)cyclopent[4,5]imidazo[2,1-b]purin-4(3H)-one

N-[(2S)-(t-Boc-amino)cyclopent-(1R)-yl]-N-(thymin-1-yl-acetyl)-glycine ethyl ester

N-[(2S)-(t-Boc-amino)cyclopent-(1R)-yl]-glycine ethyl ester

(1R,2S)-2-(N-tert-butoxycarbonylamino)-1-azidocyclopentane

(S,S)-trans-2-acetamidocyclopentanol